1. Field of the Invention
The present invention relates to an endless rectilinear motion rolling guide unit, which can be easily and simply manufactured from sheet metal material such as steel sheet or the like, yet giving rise to high precision and heavy-load resisting operation.
2. Description of the Prior Art
In the prior art technique, a sheet metal-type endless rectilinear motion rolling guide unit was manufactured such that generally right angle grooves are formed on sheet metal plates from which the unit was assembled but such a guide unit was limited in use only for light load bearing operation with a poor operationability so that it was unable to find any utility in machine tools, precision measurement equipments and like. The only utility was limited to sliding parts of cabinets, desk drawers and other office machines as they require no precision nor heavy-load operating conditions.
Further, in the prior art units made from steel sheet material, synthetic resin material was used for the formation of endless circulation passages for balls so that under such an operating condition where the number of ball circulation strokes per unit of time in the passages is great, the circulation passages were prematurely deformed or damaged to friction generated when the balls circulate therethrough, so that they could not be used with longer operation life.
Furthermore, the configuration each of the ball direction changing passages formed in the side panels of the table member for communicating the load-carrying trackway grooves for balls with the ball return passages which are formed in the sliding table member is shaped as a semicircle, so that the longitudinal dimension of the table, that is, the length thereof in its sliding direction was unavoidably became longer, thus unabling to minimize the dimension as a whole of the unit.